Abstract

This study investigated the effects of teacher written feedback and students' revision on the use of cohesive devices in expository compositions written by thirty Thai postgraduate students enrolled in a 16-week writing course at a Thai university. The teacher written comments, including corrective, advisory and indicative comments, were provided to the students' cause-effect, comparison/contrast and classification essays. The feedback on cohesion in this study dealt with form, content and, most importantly, essay organisation. Each of the essays from this experimental group was provided with a combination of teacher written comments focusing on the improvement of cohesion. The students revised their initial drafts in response to the teacher written feedback provided.

Sixty pre-test and post-test essays were written by the students from both the experimental group and the control/intact group, and 180 expository essays and revised drafts were written by the students from the experimental group. All the essays were analysed by Halliday and Hasan's (1976) cohesion analysis model and Hoey's (1991) lexical analysis model. Statistical analysis was conducted to examine the differences in the use of cohesive devices between the pre- and post-test essays and between the initial and revised drafts. The results revealed a significant improvement of cohesion in the writing of the experimental group, particularly referential, conjunctive and lexical cohesive ties. The pedagogical implications regarding the teachability and the positive effects of teacher written feedback and essays revision were derived on the basis of the research results.

The students' revised drafts were examined in terms of the student moves in response to the teacher written comments provided to their initial drafts. The investigation revealed the students' revision patterns: complete, partial and no correspondence to the teacher comments. The findings showed that most of the students who had received the teacher written feedback successfully revised their initial drafts in response to the feedback and their cohesion skills were improved.

The student questionnaire and interviews, used as triangulated studies, revealed the participants' positive attitudes towards teacher written feedback, the revision process and the use of cohesion in writing. Based on the findings in this section, the students found teacher feedback helpful for the improvement of their writing skills especially the use of cohesion, although they also expected to receive teacher feedback on grammatical accuracy. The findings also indicated that revision motivated the students to write more confidently in English and contributed to students' awareness and development of cohesion in their writing.

Insights gained from the present study are (1) that even though cohesion is a useful linguistic element that contributes to well-connected writing, it may not be adequate as a means of measuring overall writing quality, (2) that teacher feedback should be personalised to cater for each individual student's needs and each problematic writing situation, and (3) that both feedback and revision play a crucial role in raising awareness regarding the use of cohesion in L2 writing.